super budget gearbox rebuild!
Turbo Mini Forums

as life would have it, finished my exams a week ago, got the summer off uni to get stuck in and finish my rebuild then i go and break my ankle!!!

if my mobility wasn't bad enough im now signed off work for 6 weeks so will have very little money to continue rebuilding everything.

my gearbox is stripped and ready for rebuild once i order the new parts for it but which parts are ideally needed to build a reliable box?
im def buying new baulk ring and need the 3rd motion bearing as the origional has a little play backwards and forwards.
a CPU pipe is also essential i reckon as i dont brake round corners
Straight cut drops however? would the origionals not withstand the torque? i dont intend to run silly boost levels but will maybe push it upto about 10psi on a ph2 cam and 1293 bore.

finally is the diff. would a hardened diff pin be suffice or is a crosspin diff really needed?

i really want the mini finished by mid/end of summer so dont want to buy things i could do without as im really gonna be strapped for cash .

all advice greatly appreciated.

Dan

10psi on helical drops? I'd give them a couple of months at best.

About the only bearing you could maybe skimp on if they are in good condition are the diff bearings. Everything else really needs replacing, ESPECIALLY layshaft and mainshaft bearings.

If you got hold of some boxes, there is no need to change more than the bearings Tom describes. I mean, you don't need new baulk rings if the ones you've got are OK. No new shafts shold be needed either. I don't see a problem running an uprated single diffpin either, but be prepared to rebuild next summer. Also, the planet gears will need replacing if the pin is worn.
On the drops, I have no expereince, but some friends of mine in Norway use the helical ones with great success as a matter of fact.

Depends on your hoard and inclination, if u have several 998 low mileage boxes, and do what vegard suggests you could do it on the cheap. However, its difficult not to change the bearings as they are nearly always nakered.

I know im going to do a build using old bearings, but again, i'll be selecting from a LOT of s/h boxes and will pick the very best of them. The only things i will never ever skimp on are idler gear bearings as these are always a timebomb. Make sure the idler is shimmed properly aswell, it definatly wont last long otherwise.

Dont boot it in first or trash it through the gears to get the most from it. It might also help to limit full throttle till after 4,000rpm. Keeping wheelspin to an absolute minimum and laying off the loud pedal under cornering will save the diff when using a std pin and new planet gears.

I've seen the future and tbh its Pie

If you use the torrington idler bearings - that's your best chance of success with the helical idlers.

how do you know if baulk rings are in good condition?
is it if they fit tight and have no damage to the inner ribs?

i have 2 gearboxes stripped so will pick out all the best components.

last thing i want to do though is build it on such a tight budget it lasts about a month before giving up.

thanks for all the replies

Dan

You should be looking at a 1mm gap between the back of the ring and the front of the clutching teeth. Make sure you don't mix-and-match the rings either; keep them on their appropriate gears.

Hi,
Anymore opinions on helical drops and 10psi, please?
I'm interested too......
Also Turbo clutch and 10psi.... Will it hold?
Cheers,
Gavin :)

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My Mini build diary

my turbo verto lasted about 1000 miles at 10psi, which was around 120lb/ft, plus however many miles it did in the metro...

not sure about the drops either, melted 2 pistons before i found the limits of them...lol

I'm thinking of Turbo verto cover, with AP race/ rally plate......
Anyone else care to chime in......?
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

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My Mini build diary

Jukka runs helical drops on his 1380cc turbo - and has done for MANY years...

Yep, roughly 50000 kms. And they were s/h when I fitted them. I did replace the primary gear on the crank tail due to bush wear but since that was s/h too cannot really say how much was caused by turbo use. Mine are pre A+ variety like the gearbox, with smaller diamter idle gear. I would not worry about them at 10 psi as long as you shim the end floats to the factory spec.

As for the car, got it back from the paint job (only 18 months...) and it is slowly being assembled. No running this year but IMM 2007 in Denmark is scheduled ... believe it or not, by my wife.

Well life is a bitch (not the dear wife...) I just have to settle with my 285 hp Moggy.

such hardship Jukka!!

Alex

AlexF